Carrier 50TFQ008-012 Product Data page 37

gloss black with gloss — 60 deg of 65 to 90%
per ASTM D523-89. Uniform dry film thick-
ness from 0.8 to 1.2 mil on all surface areas
including fin edges. Superior hardness charac-
teristics of 2H per ASTM D3363-92A and
cross-hatch adhesion of 4B-5B per ASTM
D3359-93. Impact resistance shall be up to
160 in.-lb (ASTM D2794-93). Humidity and
water immersion resistance shall be up to mini-
mum 1000 and 250 hours respectively (ASTM
D2247-92 and ASTM D870-92). Corrosion
durability shall be confirmed through testing to
be no less than 1000 hours salt spray per
ASTM B117-90. Coil construction shall be alu-
minum fins mechanically bonded to copper
tubes.
5. E-Coated copper-fin coils shall have a flexible
epoxy polymer coating uniformly applied to all
coil surface areas without material bridging
between fins. Coating process shall ensure
complete coil encapsulation. Color shall be high
gloss black with gloss — 60 deg of 65 to 90%
per ASTM D523-89. Uniform dry film thick-
ness from 0.8 to 1.2 mil on all surface areas
including fin edges. Superior hardness charac-
teristics of 2H per ASTM D3363-92A and
cross-hatch adhesion of 4B-5B per ASTM
D3359-93. Impact resistance shall be up to
160 in.-lb (ASTM D2794-93). Humidity and
water immersion resistance shall be up to mini-
mum 1000 and 250 hours respectively (ASTM
D2247-92 and ASTM D870-92). Corrosion
durability shall be confirmed through testing to
be no less than 1000 hours salt spray per
ASTM B117-90. Coil construction shall be
copper fins mechanically bonded to copper
tubes with copper tube sheets. Galvanized steel
tube sheets shall not be acceptable. A polymer
strip shall prevent coil assembly from contacting
sheet metal coil pan to maintain coating integ-
rity and minimize corrosion potential between
coil and pan.
F. Refrigerant Components: Refrigerant circuit compo-
nents shall include:
1. Acutrol™ multiple independent circuit feed
system.
2. Filter strainer to eliminate any moisture or for-
eign matter.
3. Service gage connections on suction, discharge,
and liquid line to charge, evacuate, and contain
refrigerant.
4. Accumulator.
5. Reversing valve.
G. Filter Section:
1. Standard filter section shall consist of factory-
installed low-velocity, throwaway 51-mm (2-in.)
thick fiberglass filters of commercially available
sizes.
2. Filter face velocity shall not exceed 1.52 m/s
(300 fpm) at nominal airflows.
3. Filter section shall use only one size filter.
4. Filters shall be accessible through an access
panel with ''no-tool'' removal.
H. Controls and Safeties:
1. Unit Controls:
a. Unit shall be complete with self-contained
low-voltage control circuit.
b. Unit shall incorporate an outdoor coil
defrost system to prevent excessive frost
accumulation during heating duty, and shall
be controlled as follows:
1) Defrost shall be initiated on the basis of
time and coil temperature.
2) A 30/50/90-minute timer shall activate
defrost cycle only if coil temperature is
low enough to indicate a heavy frost
condition.
3) Defrost cycle shall terminate when de-
defrost thermostat is satisfied and shall
have a positive termination time of
10 minutes.
2. Refrigerant Controls:
Unit shall contain
charge/low-pressure, and freeze protection
switches.
3. Standard Safeties:
Unit shall incorporate compressor overtemper-
ature and overcurrent safety devices to shut off
compressor.
I. Operating Characteristics:
1. Unit shall be capable of starting and running in
cooling at 51 C (125 F) ambient outdoor tem-
perature, meeting maximum load criteria of
ARI Standard 210/240 at ±10% voltage.
2. Compressor with standard controls shall be
capable of cooling operation down to –4 C
(25 F) ambient outdoor temperature.
3. Compressor shall be capable of operation in
heating duty down to –23 C (–10 F) ambient
outdoor-air temperature.
4. Unit shall be capable of simultaneous heating
duty and defrost cycle operation when using
electric heaters indicated in Section L, Special
Features.
J. Electrical Requirements:
All unit power wiring shall enter unit cabinet at a sin-
gle factory-predrilled location.
K. Motors:
1. Compressor motors shall be cooled by refriger-
ant passing through motor windings and shall
have line break thermal and current overload
protection.
2. Indoor blower motor shall have permanently
lubricated bearings and inherent automatic-
reset thermal overload protection.
3. Totally enclosed outdoor-fan motor shall have
permanently lubricated bearings, and inherent
automatic-reset thermal overload protection.
high-pressure, loss-of-
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